Is this a common neutral - is it allowed???

Reply

  #1  
Old 03-07-11, 05:44 PM
Member
Thread Starter
Join Date: Jan 2005
Location: USA
Posts: 604
Received 0 Votes on 0 Posts
Arrow Is this a common neutral - is it allowed???

Hi,

I'm changing a circuit and going from 15A to 20A, so I'm rewiring it with 12ga NMW.

There was a ceiling light box being fed from a receptacle and then feeding two switches in one box for two different ceiling lights. The feeder from the ceiling light was using a 3 wire cable with a "common neutral" for each light switch and the red as the positive for one switch and the black for the other.

Since I'm replicating this part of the circuit in 12ga, I want to be sure I can do this or not.

It's all one breaker, so is that allowed or do I need to run two 2 wire cables from the ceiling box? Is it safe?

Thanks guys.
 
Sponsored Links
  #2  
Old 03-07-11, 05:58 PM
pcboss's Avatar
Forum Topic Moderator
Join Date: Jul 2002
Location: Maryland
Posts: 14,978
Received 35 Votes on 30 Posts
I do not think you are dealing with a neutral. I think you have 2 switch loops in one cable. The white should have been re-identified as a hot conductor and feeds power to both switches. The black and red are two switch controlled hots.

Can you confirm if the white connects to both switches?
 
  #3  
Old 03-07-11, 06:02 PM
Justin Smith's Avatar
Member
Join Date: Dec 2010
Location: Cressona, Pa, USA
Posts: 2,546
Received 0 Votes on 0 Posts
It is perfectly legal. That is often done for ceiling fans with sepreate light/fan control, and there is one in this very room.
 
  #4  
Old 03-07-11, 06:08 PM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: Twin Cities, MN
Posts: 13,020
Received 68 Votes on 60 Posts
Just for future reference there is no "positive" in AC wiring. There is hot (your "positive") neutral and ground.

From what you describe they have two switch legs and one neutral. This is 100% fine. I would wire it the same or run two cables if you wish. Either way is fine as long as you box can handle the extra wires at the larger size cubic inch wise.

NMW? You must be from Canada?
 
  #5  
Old 03-07-11, 07:03 PM
Member
Thread Starter
Join Date: Jan 2005
Location: USA
Posts: 604
Received 0 Votes on 0 Posts
To clarify: pcboss - the white is neutral and goes to the lights not the switch loops like a 3 way. I'm from Jersey not Canada.

Thanks guys!
 
  #6  
Old 03-07-11, 07:57 PM
Tolyn Ironhand's Avatar
Group Moderator
Join Date: Nov 2007
Location: Twin Cities, MN
Posts: 13,020
Received 68 Votes on 60 Posts
Originally Posted by syakoban View Post
I'm from Jersey not Canada.
I am not familiar with NMW I thought this was the equivalent to NM-b in Canada, which is why I mentioned it. Could you please let me know what it is? (I googled NMW and got NMWU, If this is what your using I think your making more work for yourself.)
 
  #7  
Old 03-08-11, 06:26 PM
Member
Thread Starter
Join Date: Jan 2005
Location: USA
Posts: 604
Received 0 Votes on 0 Posts
I meant NM-B - sorry. I think that was a mashup of everything in my head. Or, it could be the fact that everyone in Jersey has an attitude always...
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: